Packaging



H. ARENBECK May 8, 1962 PACKAGING 5 Sheets-$heet 1 Filed Jan. 9, 1961liilllll v'l'llliifllllll.

May 8, 1962 Filed Jan. 9, 1961 H. ARENBECK 3,033,439

PACKAGING 5 Sheets-Sheet 2 May 8, 1962 Filed Jan. 9, 1961 H. ARENBECKPACKAGING 5 Sheets-Sheet 3 3,033,439 PACKAGING Helmnt Arenbeck, Goslar,Germany, assignor to Natronzellstolfund Papierfabriiren A.G., Mannheim,Germany Filed Jan. 9, 1961, Ser. No. 81,305 Claims priority, applicationGermany Jan. 7, 1960 11 Claims. (Cl. 229-625) The present inventionrelates to the art of packaging.

Certain types of materials such as colfee, sugar, and the like arepackaged in containers of flexible material such as paper or the like,and a particular problem resides in closing such containers after theyare filled. Various typ s of valve arrangements are used for the purposeof closing these containers after they are filled, but all of the knownsolutions to the problem are exceedingly complex and not very reliable,and in addition they are quite expensive.

It is accordingly one of the primary objects of the present invention toovercome the above drawbacks and to provide containers of the above typewith inlet opening structures which are capable of being quickly andeasily closed in a simple and inexpensive manner.

Another object of the present invention is to provide for containers ofthe above type tubular inlets which can be closed very quickly simply byapplication of heat to the tubular inlet.

It is also an object of the present invention to provide containerswhich have tubular inlets which can be closed in an extremely short timewithout requiring any special structure for the tubular inlet beyondwhat is more or less conventional in the art.

It is furthermore an object of the present invention to provide acontainer construction which will enable the tubular inlets to closewhile the containers are moving along a conveyor after the containersare filled.

With the above objects in view the invention includes a package whichcomprises a container and a tubular inlet fixed thereto, the containerbeing entirely closed except for the tubular inlet which providescommunication between the exterior and interior of the container, andthe tubular inlet is made up at least in part of a heat-shrinkablematerial so that after the container is filled through the tubular inletthereof heat may be applied to the heatshrinkable material to shrinkthis material and thus close the tubular inlet so as to completely closethe container after it is filled.

Also in accordance with the present invention the process is providedaccording to which the container is first filled and then heat isapplied to the tubular inlet so that the heat-shrinkable materialthereof will shrink and close the tubular inlet so as to completelyclose the container.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings, inwhich:

(FIG. 1 is a fragmentary partly sectional partly diagrammaticillustration of a container according to the invention during thefilling thereof, FIG. 1 showing one pos sible embodiment of a structurefor heating the heatshrinkable material of the tubular inlet;

FIG. 2 shows the container of FIG. 1 provided with the tubular inlet ofthe invention, this tubular inlet being shown on a somewhat smallerscale in FIG. 2;

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FIG. 3 shows the structure of FIG. 2 after the container has beencompletely closed;

FIG. 4 shows a container during the filling thereof according to adifferent embodiment;

FIG. 5 illustrates the container of FIG. 4 as it is being moved awayfrom the filling apparatus;

FIG. 6 shows the container of FIGS. 4 and 5 after it is completelyclosed;

FIG. 7 is a fragmentary illustration of another embodiment of acontainer according to the present invention;

FIG. 8 is a transverse section illustrating the tubular inlet of theembodiment of FIG. 7;

FIG. 9 is an illustration of the closing of the container;

FIG. 10 is a view transversely through a conveyor showingdiagrammatically how a package is conveyed past a source of hot air forsealing the package; and

FiG. 11 is a longitudinal illustration of the conveyor of FIG. 10,showing the package openings which receive the blast of hot air.

Referring now to FIGS. 1-3, the container 1 of the package illustrateddiagrammatically therein is in the form of a bag, sack, or the like madeof paper, plastic foil, a woven fabric, or the like. For example, juteor another suitable material may be used for the container 1. Thecontainer is entirely closed except for the tubular inlet 4. Forexample, the ends of the container may be folded and the various foldedlayers may be glued to each other in a well known manner so that thecontainer is completely closed except for the tubular inlet, or in thecase of a fabric the container may be sewed so as to be closed exceptfor the tubular inlet. The tubular inlet is located at the upper leftcorner of the container, as indicated in FIGS. 1-3 where the containeris provided with the portion 2 spaced below the upper wall portion 3 so.as to provide the passage for the tubular inlet 4. The tubular inlet 4is completely housed within the container, as indicated in FIGS. 1-3,and it is made of a plastic material, in accordance with the presentinvention, as described below. The plastic wall of the tubular inlet 4may be permanently joined with the paper, fabric, or the like of thecontainer 1 as by being fused thereto in any suitable way, as by beingglued thereto, or by any other suitable well known expedient. Instead ofa tubular inlet 4 which is made up entirely of plastic, it is possibleto provide a paper tubular member which is lined along its inner surfacewith a plastic tube, and of course such a paper tube may be glued to thepaper container and the plastic liner is fused to the paper tube at theinner surface thereof in any well known manner.

In accordance with the present invention the plastic material of thetubular inlet 4 is such that it will shrink when heat is appliedthereto.

Plastic materials which are heat-shrinkable are well known, and theinvention does not reside in the choice of any one specificheat-shrinkable material but rather in the use of a tube made of such amaterial in the package combination disclosed. Thus, the plasticmaterial of the tubular inlet of the invention may be, for example, aterephthalic acid ester foil or a stretched low-pressure polyethylenefoil, or a stretched polypropylene foil, or the like. Such plasticmaterials when they have heat applied thereto will shrink quite rapidlyand to such large extent that the tubular inlet made of such materialwill become closed. The temperature to which the plastic material isheated to produce the desired shrinking is between 50 and C.

The sudden heating of the tubular plastic inlet of the invention so asto shrink the same can be provided in any number of suitable ways. Thus,as may be seen from FIG. 1, a tubular outlet 5 of the filling machinewhich contains the material which is filled into the container 1 isinserted through the tubular inlet 4, and the tubular outlet 5terminates in a downwardly directed opening 6 through which the materialsuch as coffee, sugar, or the like drops into the container 1. It willbe noted that the tubular outlet 5 of the filling machine tapers towardthe end which is provided with the opening 6. At suitable places such asthose indicated at 7 and 8 in FIG. 1 the tubular outlet 5 of the fillingmachine is provided with suitable electrodes which are connected in anysuitable unillustrated manner with a source of electrical current or thelike. These electrodes may take the form of electrical resistors whichwill become rapidly heated when current is supplied thereto, or they maybe in the form of high frequency electrodes which will also produceconsiderable heat when supplied with current. At the exterior theelectrodes 7 and 8 are covered with a material which is not electricallyconductive, such as, for example, polytetrafluoroethylene. However, itis alsov possible to provide heating by way of a heated stream of gas asair, for example.

After the container is filled, and just prior to slipping of the tubularinlet 4 off the filling tube 5, the electrodes 7 and 8 are supplied withcurrent so as to very suddenly and sharply increase the temperature ofthe tubular inlet 4 at the region where the electrodes 7 and 8 arelocated, and it will be noted that the electrode 8 extends along ahelix, at least in part. Thus, aninstant before the tube 4 is slippedoff the tube 5 an impulse of heat is applied to the tube 4 at atemperature sufiicient to shrink the latter and the tube 4 isimmediately slipped ofi the tube 5 so that immediately after leaving thetube 5 the tube 5 shrinks and thus closes the container. The shrinkingof the tube 4 reduces its interior cross section 9 (FIG. 2) to such anextent that practically a complete seal is provided as indicated in FIG.3. Moreover, because of the arrangement of the electrodes 7 and 8,particularly the helical arrangement of the electrode 8, the shrinkingof the material of the tube 4 takes place in such a way that it.contracts itself up into a labyrinth form, as shown at 4a in FIG. 3, andas a resuitof' this feature a complete seal of the interior of thecontainer 1 from the exterior thereof is provided so that protection isprovided not only against loss of the contents of the container 1 butalso against the exterior atmospheric conditions.

FIGS. 4-6 diagrammatically illustrate the filling machine 10 which isprovided with tubular outlet 5 described above and which is alsoprovided with a tiltable support 11 which carries the container 1 duringthe filling thereof as indicated in FIG. 4. FIG. 5 shows a containerafter it has been filled and the instant after the impulse of heat hasbeen applied to the tubular inlet 4 which has shrunk to the extentindicated in FIG. 5 during the substantially instantaneous removal ofthe container 1 from the filling machine 10. FIG. 6 shows the portion.9a which has completely shrunk and closed so as to close off theinterior of the container 1 from the exterior thereof.

It should be noted that instead of electrical heating, it is possible toprovide the heating of the plastic material of a tubular inlet 4 by wayof a gas such as air. For example, the tube 5 may be surrounded by asecond tube 5' which is open at its right end and closed at its leftend, as viewed in FIGS. 4-6, and the second tube communicates with asource of hot air and forms with the tube 5 an annular passage throughwhich air may be directed to the right, as viewed in FIGS. 4-6. Withsuch an atrangement at the instant when the container 1 has the positionindicated in FIG. 5 a blast of hot air is provided at a temperaturesuficient to produce shrinking of the heat-shrinkable material asdescribed above, and this arrangement also will provide closing of thetubular inlet 4, in the manner shown in FIG. 6. Moreover, thetemperature applied to the heat-shrinkable material of. the tubularinlet 4 either electrically or by way of hot air may be high enough notonly to produce shrinking but also to plasticize the material and renderit at least to some extent fiuid so that the material will not onlyshrink. out in addition at the portion which shrinks the material willfuse together and form a complete closure so as to close otf theinterior of the container 1 from the eX- terior thereof, to produce thearrangement shown in FIG. 6.

According to the arrangement shown in FIGS. 7-9 the tubular inlet isformed of a pair of portions 40 and 41. The upper portion 41 formsapproximately one half of the tubular inlet and extends longitudinallytherealong from one to the other end thereof, and this upper portion 41is made of a heat-shrinkable material such as any one of the materialsreferred to above, which will shrink when heated to a temperature ofbetween 50 and C. The lower half 40 of the tubular inlet can be made ofany suitable flexible material such as, for example, thin paper whichmay be creped and which may be provided with a waterproof coating. Ithas proved to be advantageous to use for the portion 40 of the tubularinlet a sheet of plastic which does not shrink such as, for example,polyethylene. Thelower layer 40 has side edges 42 which are bent overthe side edges of the upper layer 41 and johied thereto as by gluing,fusing, heat-sealing, or the like.

The tubular inlet may be protected against possible injury frominsertion of the filling tube, and for this purpose a covering 4-3 maybe provided all around the left end of the tubular inlet 40, 41, asindicated in FIGS. 7 and 9. Thus, the protective element 43 is foldedback upon itself so as to form an inner groove which receives the leftend of the elements 40 and 41 which form the tubular element, andelement 43 may be joined by gluing, heat-scaling, or the like to thetubular inlet 40, 41, and then the element 43 itself may be fastened tothe material of the container 1 so that in this way the element 43 alsoserves the function of fixing the tubular inlet 41, 40 to thecontainer 1. The element 43 may be made of paper, and the inner layer ofthe element 43 may be provided with longitudinally extending slits so asto facilitate the shaping of the element 43 to the configuration shownin FIGS. 7 and 9.

The tubular inlet 40, 41 of FIGS. 7-9 may be closed, after the container1 is filled, in any of the ways described above so that the material ofthe portion 41 will shrink. Of course, the material of the portion 40will not shrink.

It is also possible, as shown in FIGS. 10 and 11, to provide forshrinking of the tubular inlet 40, 41 of FIGS. 7-9 or of the tubularinlet 4 by placing the containers after they are filled on a conveyor 45with the open tubular inlet 46 directed in a certain direction so thatall of these tubular inlets 46 move along a predetermined path, and atube communicating with a source of hot air, for example, is arranged todirect a stream of air against the containers as they are moved by suchconveyor so that this stream of hot air will enter into the severalinlet tubes 46 of the conveyors 45 moving successively past the streamof hot air and thus this stream of hot air will engage each of thetubular inlets 40, 41 or 4 and shrink the heat-shrinkable materialthereof to close the tubular inlets while the containers are conveyed.

With the tubular inlet 40, 41 of FIGS. 7-9 the shrinking of the portion41 causes the portion 40 to be pulled around the shrunk portion 41 andto assume a channelshaped configuration, the shrunk portion 41 beinglocated in the channel formed by the portion 40, and with thisarrangement a complete closing off of the interior of the container fromthe exterior thereof will be provided, so that a good seal is obtained.This seal may even be improved by exerting a pressure which urges thewall of the container, such as the to wall thereof, against the tubularinlet. In FIGS. 7, 9 the portion 41 of the tubular inlet is shown indotted lines in shrunken condition.

While it is possible to locate the heat-shrinkable portion 41 of thetubular inlet 40, 41 at the lower side of the tubular inlet, it ispreferred to locate at the upper side as indicated in FIGS. 7 and 9since it has been found that this location provides the best results.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofpackages differing from the types described above.

While the invention has been illustrated and described as embodied inclosable containers, it is not intended to be limited to the detailsshown, since various modifications and structural changes may be madewithout departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can by applying current knowledgereadily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this in vention and,therefore, such adaptations should and are intended to be comprehendedwithin the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. A container adapted to be fully closed after loaded with a desiredmaterial, said container comprising, in combination, an enclosureincluding a tubular inlet and completely closed except for said tubularinlet so that the enclosure may be loaded through said tubular inlet,said tubular inlet being made at least in part of a material whichshrinks when heat is applied thereto so that after the enclosure isfilled heat may be applied to said tubular inlet to shrink and close thesame to thus completely close the enclosure.

2. A package comprising, in combination, a container adapted to befilled with a desired material and a tubular inlet connected to saidcontainer, said container being entirely closed except for said tubularinlet and said tubular inlet providing communication between theexterior and interior of said container and said tubular inlet beingmade of a material which shrinks when heat is applied thereto so thatafter the container is filled heat may be applied to said tubular inletto shrink and close the same and thus completely close the container.

3. A package comprising, in combination, a container adapted to befilled with a desired material and a tubular inlet carried by saidcontainer, said container being completely closed except for saidtubular inlet and said tubular inlet providing communication between theexterior and interior of the container so that the latter may be filledthrough said tubular inlet, said tubular inlet being made at least inpart of a material selected from the group consisting of terephthalicacid ester foil, stretched low-pressure polyethylene foil, and stretchedpolypropylene foil, so that after the container is filled heat may beapplied to said tubular inlet to shrink the heat-shrinkable materialthereof so as to close said inlet and thus entirely close the container.

4. A package comprising, in combination, a container adapted to befilled and a tubular inlet fixed to said container, said container beingcompletely closed except for said tubular inlet and said tubular inletproviding communication between the exterior and interior of saidcontainer so that said container may be filled through said tubularinlet, said tubular inlet including a pair of elongated portions joinedto each other and extending longitudinally along said tubular inlet fromone end thereof to the other end thereof, one of said elongated portionsbeing made of a heat-shrinkable material so that after the container isfilled heat may be applied to said one portion to shrink the same andthus close said tubular inlet so as to entirely close the container.

tainer, said container being completely closed except for said tubularinlet and said tubular inlet providing communication between theexterior and interior of said container so that said container may befilled through said tubular inlet, said tubular inlet including a pairof elongated portions joined to each other and extending longitudinallyalong said tubular inlet from one end thereof to the other end thereof,one of said elongated portions being made of a heat-shrinkable materialso that after the container is filled heat may be applied to said oneportion to shrink the same and thus close said tubular inlet so as toentirely close the container, said one portion of said tubular inletforming the upper half of said tubular inlet.

6. A package comprising, in combination, a paper container adapted to befilled and fixed to a tubular paper member, said tubular paper memberbeing in turn joined with a tubular inlet composed at least in part of aheatshrinkable material and providing communication between the exteriorand interior of said container, said container being entirely closedexcept for said tubular inlet so that after the container is filled heatmay be applied to said heat-shrinkable material to shrink the latter andthus close the container completely.

7. In a process for packaging material in a container which iscompletely closed except for a tubular inlet which is fixed to thecontainer and which is made at least in part of a heat-shrinkablematerial, the steps of filling the container through said tubular inlet;and, after the container is filled, applying heat to said tubular inletat a temperature sufficient to shrink the heat-shrinkable portion of thetubular inlet so as to close said inlet and thus completely close thecontainer.

8. A packaging process comprising the steps of filling a container whichis completely closed except for a tubular inlet which is fixed to thecontainer and which is made of heat-shrinkable material through saidtubular inlet; and after the container is filled applying heat to saidtubular inlet along an at least partly helical area at a temperaturesufficient to shrink the material of the tubular inlet so that when thetubular inlet shrinks as the result of application of heat thereto itwill assume a labyrinth configuration and will completely close thecontainer.

9. A packaging process comprising the steps of filling a container whichis completely closed except for a tubular inlet which is fixed to thecontainer and made of a heat-shrinkable material through the tubularinlet until the container is completely filled With a suitable material;and, after the container is filled, directing a stream of hot gas havinga temperature sufiicient to shrink the material of the tubular inletagainst the latter to shrink and thus close the same and in this waycompletely close the filled container.

10. A packaging process comprising the steps of filling a containerwhich is completely closed except for a tubular inlet which is fixed tothe container through the tubular inlet thereof, said tubular inletbeing made of a heat-shrinkable material; and, after the container isfilled, applying to said tubular inlet heat having a temperaturesulficient not only to shrink the material of the tubular inlet but alsoto render the material of the tubular inlet fluid enough to cause thetubular inlet not only to shrink but also to fuse together in order tocompletely close the container.

11. A packaging process comprising the steps of filling a series ofcontainers each of which is completely closed except for a tubular inletwhich is made up at least in part of a heat-shrinkable material throughthe tubular inlet thereof; placing the thus filled containers on aconveyor with all of the tubular inlets thereof facing in the samedirection so that the tubular inlets of the filled 7 3 containers movealong a predetermined path on the References Cited in the file of thispatent conveyor; and directing against the tubular inlets as they moveon the conveyor along said path a blast of UNITED STATES PAThNTS hot airhaving a temperature sufficient to cause the heat- 2,790,286 Snyder Apr.30, 1957 shrinkable material of the tubular inlet to shrink and thus 52,865,765 Allen Dec. 23; 1958 close each of the containers as they moveon the conveyor. 2,918,958 Chandler Dec. 29, 1959

